Pump apparatus



April 30, 1968 L. VAN LENTEN ET AL 3,380,673

PUMP APPARATUS Filed May 12, 1966 INVENTORS.

LEE VAN LE/VTEA/ BY C 'H LES M. VA

DYk ATTORN United States Patent 3,380,673 PUMP APPARATUS Lee Van Lenten, Allendale, and Charles M. Van Dyk,

Paterson, N.J., assignors to International Telephone and Telegraph Corporation, Nutley, N.J., a corporation of Maryland Filed May 12, 1966, Ser. No. 549,562 9 Claims. (Cl. 241191) ABSTRACT OF THE DISCLOSURE A pump is provided in which the housing encloses a cylindrical chamber having an offset axial inlet and a tangential outlet, and an impeller is mounted within said chamber having two angular vanes, each vane being formed to provide a radial cutting edge and a side shearing edge, to effectively cut paper wads and other fibrous material.

This invention relates to pump apparatus, and more particularly to a raw sewage pump.

There is an ever-growing need for a small, low-cost pump which will handle the disposal of the contents of single toilet units such as are installed in travel trailers, mobile homes, boats, marinas, roadside service stations, summer camps, and the like. The contents of these units may be discharged into a holding tank, a chemical-treatment system, a specially provided connection to sanitary sewage-disposal, plants, or in the case of present marine usage discharged overboard, after chemical treatment, in designated areas. With the ever-increasing public demands for pollution control, the development of such equipment is of primary importance.

Therefore, an object of this invention is to provide a low-cost pump capable of handling toilet contents without clogging the pump or system.

A further object of this invention is to provide a pump capable of cutting up raw sewage so that chemical treatment is accomplished more rapidly and effectively.

A still further object of this invention is to provide a pump having reserve cutting action capable of handling a reasonable quantity of paper towels of wet-strength quality without clogging the pump or stalling out the pump driving motor.

Another object of this invention is to provide a pump capable of handling both raw and treated sewage and therefore, serving the dual function of pumping from the toilet into a holding or treatment tank, and subsequently discharging the sewage at a disposal point.

An additional object of this invention is to provide a pump suited to the final disposal of sewage from combined toilet and chemical treatment units.

Yet another object of this invention is to provide a pump having the above features and capable of functioning in an automatic cycle system or a manual system.

A feature of this invention is to provide a pump adaptable to the disposal of the contents of a liquid-type sanitary toilet unit, embodying an impeller rotating on the center-line of a cylindrical chamber having an offset axial inlet and a tangential outlet. The impeller of the pump is provided with two angular vanes, opposed in position, each vane being formed to provide a radial cutting edge and a side shearing edge, to effectively cut paper wads and other fibrous material and to simultaneously mix said material with water to form a pumpable slurry and subsequently discharging same through said pump outlet.

With the foregoing, other features and objects of this invention will become more apparent by reference to the following description taken in conjunction wih the ac companying drawings in which:

FIGURE 1 is a partial cross-section of a pump according to the invention;

FIGURE 2 is a suction-end view of the pump shown in FIGURE 1;

FIGURE 3 illustrates the configuration of the impeller used in the pump according to invention;

FIGURE 3a is a partial end view of the vane of the impeller taken along line 3a of FIGURE 3;

FIGURE 3b is a partial end view of the vane of the impeller taken along line 3b of FIGURE 3;

FIGURE 3c is a partial end view of the vane of the impeller taken along line 3c of FIGURE 3; and

FIGURE 3a is an end view of the vane of the impeller taken along line 3d of FIGURE 3;

Referring to FIGURE 1, a housing 1 enclosing a cylindrical chamber 2. is adapted to mount drive means 3. Shaft 4 from drive means 3 extends into chamber 2, and hub 5 has provision for conventionally position and locking onto shaft 4. An impeller 6, preferably a stainless steel stamping, is staked or otherwise fastened to hub 5. A standard mechanical seal 7 closes and seals chamber 2 about shaft 4. Chamber 2 is covered by cover-plate 8 having through its face pump suction inlet 9 and hub 10 to which the pump suction supply (not shown) may be attached. Plate 8 is attached to housing 1 through mounting holes 11. In certain applications the cover-plate 8 may be omitted and the main housing 1 attached to a tank of the complete disposal system, provided this attachment has a suitable and properly located suction opening replacing inlet opening 9.

Referring additionally to FIGURE 2, the discharge outlet 12 from chamber 2 is preferably located below the pump horizontal center line and on the same side of the vertical center line as inlet 9. Outlet 12 is provided with a hub 13 or other suitable means of attaching a pump discharge conduit (not shown). Impeller 6 has a web 14 joining two opposed angular vanes 15. The rotation of impellet 6 is in the direction indicated by arrow 16 which is in the direction of outlet 12 and across the path of inlet 9. With reference again to FIGURE 1, the Width of chamber 2 should 'be substantially three times the radius of outlet 12 with the center line of inlet 12. located approximately 2R from inlet opening 9. The impeller 6 should be spaced 1R from opening 9, and the diameter of chamber 2 should be approximately 2R plus the impellerdiameter. Both the inlet and outlet diameter being approximately one-half the diameter of chamber 2. Considerable laboratory effort has been expended to establish this configuration, and it should be evident to one skilled in the art that reasonable variation of these parameters is possible.

The configuration of impeller 6 can best be understood by reference to FIGURES 3 through 3d. The impeller 6 operates as an impeller due to the deformed vanes 15 set at angle 01, approximately 42 /2 with respect to the impeller horizontal center-line and sloping backward in the direction of rotation, arrow 16. Impeller 6 as shown with web 14, is constructed as a two vane stainless steel stamping, having the vanes formed one to the front and the other to the back as shown in FIGURES 3a and 3c respectively.

In addition, impeller 6 also operates as a cutting knife to break up tissue and other solids and mixing this material with water or chemical to form a slurry which will be pumpa'ble through the discharge line for further treatment or disposal. To do this, cutting edges are provided on vanes by grinding or otherwise forming the angles shown in FIGURES 3a through 3d.

Referring to FIGURES 3a and 3c, the outer portion of each vane is formed by angle 02, approximately 87, oh. the flat surface of web 14, leaving an angle 03, approximately 50, as a shearing edge 17 for practically the entire vane length as shown in FIGURE 3d. A second operation shown in FIGURE 3b is set at an angle 64, approximately 15, off the opposite flat surface of web '14, removing that portion of the vane between the vane vertical center-line and the inner tip 18 of the vane. This produces a radial cutting edge 19, at angle 95, approximately 39 /2", extending from inner tip 18 to and intersecting the beforementioned shearing edge at the impeller vertical centen line as shown in FIGURES 3 and 3d. The outer tips 26 of the vane are substantially twice the radius of the inner tips 18.

This geometry produces a uniquely novel cutting action, wherein each vane travels in its own radial path, the angle of the vane in relation to rotation produces excellent shearing action, the radial cutting portion has no hook or shoulder to hold fibers at its beginning point, then angles to the full impeller width, thereby developing a lateral shearing action, and finally radial shear is produced on each side of the impeller for the full vane Width.

The impeller has been shown as a metal stamping and the cutting edges produced by the removal of the metal, however with the use of modern technology in powder metal or ceramics, this impeller could be produced as a complete part. While specific angles have been disclosed for reasons of clarity, any reasonable deviation from these angles to produce the same results should be considered within the scope of this invention.

It is obvious that a pump for this service should be as small as possible and require a minimum of power to operate. Because of the fibrous material to be handled, the proportions of the inlet, the outlet, and impeller must be such as to provide adequate room for wads of fiber without permanently blocking the flow. Laboratory tests of units indicate that inlet 9 should not be smaller than 1 /2 in diameter, and outlet '12 no less than 1% in diameter. In operation, sewage enters the pump through suction inlet d which is located above the pump center line and on the same side of the vertical center line as outlet 12 as illustrated in FIGURE 2. This position of entry provides maximum cutting action by the impeller, reducing the raw sewage to a slurry which can readily flow into outlet 12 due to the pressure diiferential between suction and discharge openings resulting from the centrifugal action of the impeller. Laboratory studies show that more time will be required to cut up large wads of paper; however, the cutting action continues until the slurry is formed, with no clogging of the pump or stalling out of the driving motor.

While we have described above the principles of the invention in connection with specific apparatus it is to be clearly understood that this description is made only by way of example and not a limitation to the scope of the invention as set forth in the objects thereof and in the accompanying claims.

We claim:

1. Pump apparatus comprising:

a housing having axially spaced end walls enclosing a cylindrical chamber, said housing including an offset axial inlet in one of said end Walls and a tangential outlet in the peripheral Wall of said cylindrical chamber;

drive means mounted in the opposite one of said end walls of said housing;

an impeller with a plurality of vanes, centrally mounted in said chamber and arranged to be driven by said drive means, such that said impeller rotates toward said outlet with a cutting action across the path of said inlet; and

said chamber provides a forward clearance in front of said impeller approximately equal to the radius of said tangential outlet, and a rearward clearance substantially equal to the diameter of and in substantial alignment with said tangential outlet.

2. Apparatus according to claim 1, wherein the other of said end walls contains said oilset axial inlet, said inlet being proportioned to have a diameter approximately one-half the diameter of said chamber and located in an upper quadrant above said outlet; and said tangential out let leaving said chamber having a diameter approximately one-half the diameter of said chamber.

3. Apparatus according to claim 1, wherein said impeller is provided with two vanes formed at opposite ends of a web section, such that one vane projects forward toward said inlet from said web, and the other vane projects rearward from said web.

4. Apparatus according to claim 3, wherein said two vanes each include an outer tip (20) and an inner tip (18), such that both said vanes are positioned at an angle produced by making the radius of the outer tip of said vane substantially twice the radius of the inner tip of said vane.

5. Apparatus according to claim 4, wherein each of said impeller vanes is provided with a radial cutting edge and a side shearing edge, to elfectively cut fibrous material entering said inlet and simultaneously mixing said material with the pumping liquid to form a pumpable slurry and discharging same through said pump outlet.

'6. Apparatus according to claim 5, in which said radial cutting edge is positioned from the vane vertical centerline to the inner tip of said vane, and said shearing edge is positioned angnlarly with respect to said web and occupies substantially the entire vane length, such that said cutting edge and said shearing edge is in the direction of rotation to produce the proper cutting and shearing actions.

7. Apparatus according to claim 1, in which:

said offset axial inlet is proportioned to have a diameter approximately one-half the diameter of said chamber; said tangential outlet leaving said chamber having a diameter approximately one-half the diameter of said chamber; and

said impeller having two angular vanes, opposed in position, each vane having a shearing edge and a radial cutting edge, said impeller rotating at .a high speed in substantial ofiset alignment with and across the path of said inlet, for cutting fibrous material reducing said material to .a slurry and subsequently discharging said material for disposal. 8. Apparatus according to claim 1, wherein a portion of the wall of said axial inlet is in axial alignment with an upper portion of the inner peripheral wall of said chamber, a portion of the wall of said tangential outlet is in alignment with the lowest portion of the inner peripheral wall of said chamber, and said rotating impeller is provided with vanes positioned at an angle with both the axis and the Web of said impeller.

'9. Apparatus according to claim '8, in which: said impeller vanes are positioned at an angle of 42 /2 with respect to the impeller horizontal center-line and sloped backward in the direction of rotation;

each of said vanes being formed at a 87 angle with the fiat surface of said web in the sloping direction, leaving a 50 shearing edge for substantially the entire length of said vane; and

each of said vanes having a radial cutting edge being formed by an angle 15 with the =fi-at surface of said web opposite to the sloping direction, leaving a 39 /2 radial cutting angle extending to and intersecting said shearing edge at the impeller vertical center-line; whereby said radial cutting edge and said shearing edge eilectively cut paper wads and other fibrous material and simultaneously mix said material with water to 5 6 form a pumpable slurry and discharging same 2,635,548 4/1953 Brawley 103103 through said pump outlet. 3,155,046 11/1964 Vaughan 103111.1 3,308,764 3/1967 Walker 103103 Reerences C:ted FOREIGN PATENTS UNITED STATES PATENTS 5 542 597 5/1922 France 479,642 7/1892 Hamilton 230134.45 I 2,352,127 6/1944 Sheldon 241191 HENRY F, RADUAZO, Primary Examiner.

2,456,128 12/1948 Kesslex .103103 

